Yes, Falk, a fourth-string rookie who won’t even play, has altered preparations by both teams. Miami signed him last week after he was released by Tennessee on cutdown day, and the Dolphins are sure to pick his brain about the Titans’ scheme under rookie coach Mike Vrabel.

All of which adds lends another layer of unpredictability to the season opener.

Here are things to know about two teams who didn’t excite preseason prognosticators:

QB MATCHUP

Ryan Tannehill returns after missing the Dolphins’ past 20 games, and says he’ll be ready rather than rusty. He’s coming off reconstructive knee surgery that wiped out his entire 2017 season, and says he never doubted he would be ready for the 2018 opener.

“I always felt confident that this would be where we ended up,” he said. “It’s finally here and I’m ready to go.”

While Tannehill has never played in the postseason, counterpart Marcus Mariota is trying to become the first quarterback to lead the Titans to the playoffs in back-to-back years since Steve McNair in 2002-03.

That will require proving wrong the oddsmakers who predict Tennessee will win eight games. Miami, led by third-year coach Adam Gase, is widely projected to repeat last year’s 6-10 record.

THE OTHER QB

While Falk will be able to provide the Dolphins some insight into Sunday’s matchup, Vrabel says it could have been worse.

The Titans’ new coach wanted to install the entire offense during training camp, but offensive coordinator Matt LaFleur — mindful the team would have to waive some players — talked him out of it.

“He wanted to hold some stuff,” Vrabel said. “I said, ‘OK, I’ll defer to you on this one.’ As it turns out, he was kind of right. There’ll be some things that I’m sure Luke can give them. But then again, I am glad that Matt was adamant about holding some stuff until cutdown day. I think he had been burned by some of that stuff in the past.”

The Dolphins kept some of their playbook under wraps during the preseason, too. They’re expected to have packages for veteran newcomer Albert Wilson and rookie tight end Mike Gesicki that they didn’t show in exhibition games.

“There were a few plays going into Week 3 that Gase wanted to run,” Tannehill said with a smile. “I said, ‘Hey, those are great plays. Let’s save those.’ We have some things that we haven’t shown that we’re excited about.”

HOMECOMING

NFL active rushing leader Frank Gore will make his Dolphins debut, and at 35 he’s thrilled to return to South Florida, where he was born and raised and starred for the Miami Hurricanes.

Gore will play in his 113th consecutive game, and he needs 76 yards to become fourth-leading rusher in league history.

HEY, I KNOW YOU

Miami and Tennessee added former Patriots teammates during the offseason. Receiver Danny Amendola joined the Dolphins, while the Titans acquired cornerback Malcolm Butler. The Titans’ other starting cornerback, Logan Ryan, is another Amendola friend and former Patriots teammate.

Tennessee’s secondary also includes All-Pro safety Kevin Byard and cornerback Adoree Jackson, who started every game as a rookie last year.

“We’re super excited to see what we’ve got,” Ryan said. “It’s the most excited I’ve been to start a season off.”

STREAKING IN TENNESSEE

The Titans have won five consecutive road openers, the NFL’s longest such streak. Three of those came in season openers. The streak includes three coaches, and three of the victories came by 16 points or more, including last year’s 37-16 victory at Jacksonville in Week 2.

“The mindset is to win,” linebacker Brian Orakpo said. “I mean, it’s point blank, period, win. Win ballgames. Take it week by week and win, no matter if it’s 50-49 or 3-0.”